POS0907 ULTRA-HIGH FREQUENCY ULTRASOUND TO ASSESS SKIN INVOLVEMENT IN SYSTEMIC LUPUS ERYTHEMATOSUS: PRELIMINARY DATA FROM A MONOCENTRIC COHORT
Authors: C. Cardelli, V. Signorini, G. Granieri, C. Stagnaro, L. Carli, F. Ferro, E. Elefante, D. Zucchi, F. Trentin, G. Monaco, C. Tani, V. Dini, M. Romanelli, M. Mosca
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> The assessment of cutaneous involvement in Systemic Lupus Erythematosus (SLE), particularly the differential diagnosis between active lesions and damage, might be a challenge for the clinicians. Ultra-high frequency ultrasound (UHFUS), with a sub-millimeter resolution, is a promising tool in the evaluation of superficial structures. In recent years its use has grown in the field of dermatology, where UHFUS finds application in the study of normal anatomy, differentiation of cutaneous lesions (bullous and inflammatory disease), diagnosis of skin malignancies and pre-surgical mapping, increasing diagnostic sensitivity and accuracy in guiding medical and surgical therapies. <h3>Objectives</h3> The aim of the study was to explore a possible role of UHFUS assessment in the evaluation of skin involvement in a monocentric cohort of SLE patients and to evaluate the relationship with patients' perception of their skin disease. <h3>Methods</h3> Consecutive adult SLE patients (1997 ACR criteria) regularly followed at our Lupus Clinic were prospectively enrolled during a scheduled outpatient visit in presence of skin lesions. Demographical, clinical, laboratory and treatment data were collected at enrolment. Disease activity and organ damage were evaluated with the SELENA-2K and SLICC-DI, respectively. Clinical assessment of skin lesions was done by an experienced rheumatologist using the Cutaneous LE Disease Area and Severity Index (CLASI); at the same time, UHFUS evaluation of skin lesions was performed with a 70 MHz probe by an experienced dermatologist. The Skindex-16 questionnaire was used to assess the impact of the skin involvement on patients' quality of life. <h3>Results</h3> We included 70 assessments in 55 SLE patients with skin lesions (5/55 evaluated twice, 5/55 three times). Cutaneous disease subtypes were distributed as follows: acute 37.5%, subacute 12.5%, chronic 50.0%. The characteristics of the cohort are shown in Table 1. The most frequent UHFUS alteration was the presence of power Doppler (51/70, 72.9%), followed by dermal oedema (37/70, 52.9%), dermal inhomogeneity (33/70, 47.1%), follicular plugging (32/70, 45.7%), vascular ectasia (27/70, 38.6%) and thinning of the epidermis (10/70, 14.3%). The CLASI activity score was significantly higher in cutaneous areas with power Doppler signal (<i>p</i>=0.032). Dermal oedema was also found to be associated with higher CLASI activity scores, considered both globally (<i>p</i>&lt;0.001) and at the level of the US-evaluated region (<i>p</i>=0.002), and with higher damage scores of the evaluated area (<i>p</i>=0.034), while vascular ectasia was only associated with higher damage scores of the evaluated area (<i>p</i>=0.036). Skindex-16 symptoms subscale scores were significantly higher in patients with thinning of the epidermis (<i>p</i>=0.01) and dermal inhomogeneity (<i>p</i>=0.049). Regarding the subtype of cutaneous involvement, vascular ectasia was significantly more frequent in chronic cutaneous LE (<i>p</i>=0.029), while no other UHFUS alterations were found to differ between the three groups. <h3>Conclusion</h3> Although preliminary, our data seem to suggest UHFUS as a promising tool not only for assessing skin involvement in SLE, but also for monitoring disease activity over time with a view to optimising the management of these patients. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.